Frank Backx, professor of sports medicine at Utrecht University, concluded on the basis of several studies that there is no difference between the total number of injuries on synthetic turf and natural grass. "Artificial turf is no more dangerous than natural grass," he says.
On the basis of the available studies, there is an increased risk of synthetic turf with ankle injuries, but there is no difference in terms of knee injuries and playing on synthetic turf possibly helps in preventing lower leg injuries.
The research of Thijs Velema, of the National University of Taiwan, makes clear that ithere is no difference between playing on synthetic turf and natural grass. 'The number of goals is equal, as is the number of yellow and red cards shown to players during the match. The results also don't really differ"
Here is the Dutch report.